


Matsuno Brothers: Infinity War

by nega_mek0



Category: Dangan Ronpa - All Media Types, Gintama, おそ松さん | Osomatsu-san (Anime)
Genre: Crossover, Gen, Oneshot, despite what the title says this has nothing to do with avengers, idk how to write complete stories, mostly dialogue and banter oops
Language: English
Status: In-Progress
Published: 2019-11-28
Updated: 2020-02-25
Packaged: 2021-02-25 22:40:42
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 2,602
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21593212
Author URL: https://archiveofourown.org/users/nega_mek0/pseuds/nega_mek0
Summary: Various Osomatsu-san crossover oneshots with fandoms I know. I just love writing about the brothers ok, they're so fun to writeMay expand into its own fic if I feel like it/have more inspiration. But don't count on it lol
Kudos: 5





	1. Who decided that the one wearing red is always the leader in super sentai shows? No matter what colour their skin-tight spandex suit is, it’s always what’s on the inside that matters, isn’t it?! (Gintama)

**Author's Note:**

> The Yorozuya gang receive a peculiar client. Or six of them, to be more specific.

"So you're looking for your missing brother…uhm, Jyushimatsu-san?" Gintoki repeated the request, staring at the duplicate faces looking back at him and his associates.  
"Karamatsu. I'm Jyushimatsu." One of the clones in a yellow yukata sitting to the second right corrected him.  
"Right, I apologise. So where was it where you last saw Todomatsu-san?"  
"Karamatsu. Todomatsu is my name." The clone sitting to the far left, dressed in a pink variant of the same yukata, corrected him again, crossing his arms.  
"Yes, of course. So tell me, Karamatsu-san—"  
"No, Karamatsu is the one we're looking for. Are you doing this on purpose?" The green yukata clone on the second left sounded irritated.  
  
"Gin-san, I know this situation seems bizarre, but could you take this more seriously? Client opportunities don't come very often, you know," Shinpachi chided him from his seat on the sofa.  
"Did this Karamatsu escape from the cloning lab you all came from?" Kagura asked passively, taking a sip from her cup of Nilo.  
"Kagura-chan! Don't make things worse!" Shinpachi stiffened as he tried to salvage the situation, glancing towards the potential clients to gauge their reaction.  
_At this rate, they're gonna think we're no good…!_  
  
They seemed to be holding a hushed conversation amongst themselves too.  
"Choromatsu-niisan, are you sure coming to these people for help is a good idea? They aren't taking us seriously…" Pink whispered to Green next to him, eyes narrowed in distrust.  
"We don't have any other choice, do we? He's been gone for two weeks now, and Mom and Dad's getting worried. This place is the only odd-jobs business we could find that doesn't charge exorbitant prices," Green whispered back tensely.  
"Why do we need to go through all this trouble to look for him?" Purple interjected, clear disinterest in his voice. "Remember a few months back when he went on his 'journey of self-discovery'?"  
"Yes, but he came back after three days, and he even left a note in advance. But this is so sudden, and he's not even answering his phone!" Green bit his lip, a look of panic appearing on his face as he began to fumble with his words. "We don't even know for sure if something happened to him! What if—what if he's in trouble, or worse, dead in a ditch, o-or—"  
  
"Choromatsu, _cut it out!_ "  
Green, no, Choromatsu’s increasingly loud and frantic voice was interrupted by an authoritative one, belonging to the man sitting in the middle and dressed in red (rather appropriately, as if he's in a sentai show). Arms crossed, he glared at Choromatsu and gestured to the trio in front of them. Reaching a silent understanding, the group's conversation grinded to a halt.  
  
Nodding, as if to psych himself up, Red cleared his throat and addressed the Yorozuya trio, his solemnity evident in his voice.  
"Our brother could be in danger, so we really need whatever help we can get. We'll pay any amount you ask for, so can you please hear us out?"  
“Of course!” Shinpachi jumped at the opportunity, not wanting them to lose faith in their business. “Please tell us the circumstances of his disappearance.”  
  
Red sighed. “First, maybe I should make our identities clear. We’re sextuplets. It’s uncommon, but it’s really true. I’m Osomatsu, and these are my younger brothers, Choromatsu, Ichimatsu, Jyushimatsu and Todomatsu,” he introduced them chronologically. “Karamatsu’s the second oldest, and the one who went missing two weeks ago. That clear?”  
Gintoki seemed to have understood the gravity of the situation, and changed his tone appropriately. He nodded.  
  
“Right. It all began when Karamatsu and I went to play pachinko together two Wednesdays ago. I go there at least once a week, so it's not an unusual affair."  
“I see. Is Karamatsu-san a frequent gambler?”  
“Well, not really. I just brought him along as an extra wallet in case I ran short.”  
  
Shinpachi couldn't help but note the sleazy personality peeking through their client's words.  
_Sounds like a certain someone, wouldn’t you agree, Gin-san..._  
  
“Anyway, after I emptied his...I mean, after we emptied both of our wallets, the two of us headed home at about early evening. On the way, he said that he remembered having arranged to meet up with Chibita, our childhood friend who runs an oden cart the next street over.  
“So I told Karamatsu that I’d head home first, trusting he’d come home later.  
"But he didn’t. The next morning, he was still nowhere to be found. We assumed he stayed the night at Chibita’s place, but when we went over to ask him, he said that while he and Karamatsu did have plans together, it wasn’t for that day and he hadn’t seen him at all.”  
  
Kagura leaned forward, cheek resting on her palm, totally enraptured in the man’s story. “So you’re saying that Karamatsu lied?”  
Choromatsu shook his head, but had an uncertain look on his face. “I find it hard to believe that. Karamatsu-niisan may lie to himself about his taste in fashion, but he’s actually quite honest. If he told Osomatsu-niisan a lie, there had to be a damn good reason for it.”  
  
“Oh.” Osomatsu suddenly spoke aloud, eyes widened as if having realised something.  
“Thinking about it now...Chibita’s oden cart is on the street just across from our house. But when we left the pachinko parlour, Karamatsu went in the opposite direction…”  
“What?!” Todomatsu shrieked. “Why didn’t you bring that up earlier? In fact, why didn’t you realise it sooner, huh?!”  
Osomatsu shrugged sheepishly. “I assumed that he was taking a detour or something. Back then, I didn’t think anything would happen, so I never really paid attention to what he was doing.”  
  
Gintoki hummed, deep in thought. “That doesn’t give a lot to go on. Where exactly is that pachinko parlour?”  
Osomatsu pointed to its general direction. “East from here. It’s the closest one to our house, since it’s on the same street.”  
“East from here...ah, that’s the one I frequent too.” Gintoki squinted at the oldest sextuplet’s face. “Speaking of which, I think I might have seen you around before...”  
“Wait, Gin-san. If Karamatsu-san headed in the opposite direction, then that means…” Shinpachi realised.  
Kagura clapped her hands together, noticing it too. “Yeah, if he went west instead, that means he headed here, towards Kabukicho!”  
  
“Hold on a moment…” Gintoki stared even harder at Osomatsu’s face. “Have you been in Kabukicho recently, Osomatsu-san? I’m pretty sure I’ve seen your face outside the pachinko parlour before.”  
“No, I haven’t…wait, have you seen Karamatsu before, Sakata-san?!” Osomatsu shouted.  
All eyes were on Gintoki as he attempted to reach back into his memory of the past week.  
“Oh yeah, I was at old man Gengai’s workshop with Tama after Otose told me to get spare parts for her last week. Usually, his clients are kids who want to buy mechanical toys from him...but I remember that day, there was this older guy there talking with him,” he glanced over the brothers as he continued, “and he was wearing a yukata with this tasteless black jacket over it.”  
Gintoki’s next few words fitted the final puzzle piece in the brothers’ minds.  
  
“Tell me, do any of you usually wear blue?”  
  
A thick silence permeated the room for a few moments before disappearing in a flurry of voices.  
“No way…that’s him!”  
“What a coincidence…”  
“Gin-san, you seriously saw our missing client just last week?! At Gengai-san’s no less?!”  
“Do you remember what Karamatsu was talking with that guy about?” Choromatsu pressed him for more details, sweat visibly dripping down his face.  
Gintoki scratched his head. “Hmm, well I didn’t really think much of it at the time, so I wasn't listening in on their conversation.”  
  
“That’s too bad, but at least we finally have a good lead.” Shinpachi replied optimistically.  
As soon as he said that, the three members of Yorozuya stood up in unison.  
"I guess we should get going as soon as possible." Gintoki glanced toward his clients who were staring up at them in confusion.  
  
"Well, what are you lot waiting for? Don't you want to find your brother?"  
Osomatsu blinked before realising what he meant. "Wait, are you saying we're going right now? And we have to follow?"  
"What else?" He replied with a smirk.  
"Right now, huh…"  
"Makes sense…"  
The brothers exchanged murmurs of assent as they, too, got off the sofa.  
Ichimatsu made a barely audible groan, but followed his brothers as they headed out of the room and towards the door.  
  
“Yahoo! Looks like Operation Find-the-Blue-Clone is a go!” Kagura cheered, picking up her umbrella.  
“You’re still on about that, huh, Kagura-chan…” Shinpachi sighed, a habit he found himself unable to curb. It was going to be another long day.


	2. Smile at a Worthless Life in the Name of a Meaningful Death (Danganronpa)

**Summary for the Chapter:**

> The gang gets stuck in a killing game and things go exactly as you’d expect.

**Notes for the Chapter:**

> ...yeah I couldn’t think up a thematic title for this one. This is actually just a portion of a longer crossover fic I’m working on, but in case I never complete it, it can still count as a oneshot I guess
> 
> I wanted to put the bracketed thoughts in italics, but I’m not very good at formatting so I can’t get it to work. So until I can figure out how I’ll leave it as is. Sorry.

_"KYAAAAHH!!" ___  
We ran to the cafeteria with hurried footsteps when we heard Totoko's shrill scream.  
"Totoko-chan! Are you alright?!"  
As we arrived at the entrance, we witnessed an unbelievable sight.  
_(...!) _  
It hung upside down, feet bound to the ceiling fan by rope.  
Bright pink blood dripped down below it in a rhythmic manner, steadily forming a pool of blood.  
I couldn't move.  
Hanging lifelessly from the ceiling was the body of Iyami, the Ultimate Conman and our long-time acquaintance.  
Time stood still as we all gaped at the bloody sight. I could only stare at Iyami's corpse...and say…  
  
"About fucking time."  
Choromatsu stepped forward, scratching his head. "I didn't think one of us would actually kill someone...but if we did, I knew Iyami would have died sooner or later. Who is even surprised at this?"  
  
Totoko, the ultimate Local Idol, had quickly recovered from the shock of the event and looked away, twirling her hair in disinterest.  
"It surprised me at first, but now that I see it's just Iyami, I don't really care anymore. You guys work on the investigation or whatever yourselves. See you at the trial."  
With a wave of her hand, she turned and left the room.  
  
"Wait, Totoko!" Before Chibita could even finish his sentence, Totoko was long gone. The Ultimate Oden Cart Owner sighed, rubbing his shiny head.  
"One of our friends just died…she could at least pretend to care. Though we weren't all that close really," Chibita glared hard at the six of us. "Who could've done this? It wasn't me, and though Totoko isn't exactly a nice person, she can't possibly kill anyone. It has to be one of you Ultimate NEETs, isn't it?"  
  
I raised my arms in alarm, taking a few steps back. "Woah, woah, hold on there! Firstly, we're not officially Ultimate NEETs. We can't even remember our talent. _(Or if we even have one.)_ Secondly, there was no way it was one of us brothers! And certainly not me! Though Ichimatsu could probably do something like this."  
  
Ichimatsu clicked his tongue, annoyed at the accusation.  
"Wasn't me. Could be Todomatsu."  
  
"I didn't kill him!" Totty batted his eyes, tears starting to form in them. "I could never hurt anyone!"  
"Liar." Choromatsu could be heard saying under his breath, but he was deftly ignored.  
"Maybe Jyushimatsu-niisan did it? He may look innocent, but we all know from that incident how dangerous he really is."  
  
We all involuntarily shuddered. That incident with the heater would remain in our minds forever. Jyushimatsu, however, shook his head.  
"Nuh-uh. I didn't kill Iyami. Maybe Choromatsu-niisan offed him."  
"Huh? Care to repeat that again, Jyushimatsu?" Choromatsu's tone was low and dangerous, his fist raised.  
  
Karamatsu hurriedly took off his sunglasses, stepping between the two.  
"Now, now, we brothers mustn't—"  
  
"Now, now! Stop squabbling amongst yourselves!"  
A voice cut through the violent atmosphere that was quickly building.  
Monokuma suddenly appeared in front of us, paws raised in an attempt to calm the situation.  
"Damned bear," Ichimatsu spat, "stop appearing out of nowhere. What do you want?"  
  
The bear gave a harrumph. "Geez, there's no need to be so rude to your elders. I was going to play the Body Discovery announcement earlier, but it seems like everyone's already here. And even if I _did_ play it," he jabbed his paw in the direction of the door where Totoko exited a few moments ago, "it seems like no one would care. Puhuhu…for not a single person to shed a tear over his death…Iyami's ghost must be despairing right now."  
Monokuma put his paws to his mouth and giggled.  
  
"Cut the crap, Monobastard. What are you here for?" I growled.  
"Don't get your panties in a twist. I'm only here to give you the Monopad, you bastards."  
From behind him, he pulled out a black and white tablet and handed it to me.  
"Now you'll have the info about the body to help with your investigation. Of course, you'll need to do some actual investigating to get all the evidence you need for the trial. Now get to work! You don't have much time!"  
The stupid bear gave another annoying laugh, and disappeared.  
  
"Geez, why are we even in this mess…"  
I held the Monopad out so that all of us, including Chibita and the Ultimate CEO, Hatabou _(when did he even get here?)_ could see.  
"Iyami, the Ultimate Conman...died at 10:43am today. It’s about noon now, so this happened a few hours ago, huh.” I continued to read.  
“Cause of death…blunt force trauma to the head...that’s it?” The Monopad divulged no further information, only showing a diagram of the area of impact.  
  
**[—Truth Bullet obtained: Monopad—}**  
  
“This is no good. Aside from the time of death, this thing doesn’t have anything all that useful. Anyone can tell how he died just by looking at him.” Choromatsu furrowed his brow.  
  
"Brothers…we must join forces in this crisis. The goddess of fate has placed us in this predicament, and we must do our utmost to overcome it!" Karamatsu declared in his usual manner, shaking his fist emotionally.  
"Shut the hell up, Karamatsu. Honestly, this is such a pain. I don't care if we all die, so I'm not gonna help." Ichimatsu turned his back to us, yawning.  
"As apathetic as usual, Ichimatsu-niisan." Todomatsu sniffed the air and scrunched his nose. "Wow, this place reeks of blood. I don't wanna die, but touching dead bodies is so gross. Do we really have to do this?"  
"Do you all have a death wish?! Can't we just be serious for once?! If we fuck up the class trial later, we're all gonna die, you know?!" Choromatsu shouted in exasperation.  
"Well, then you do it, Choromatsu-niisan."  
  
_(God, why are we being forced to do this?) _  
  
"If you want to live so badly, then go investigate yourself."  
  
_(There's still so much I want to do.)_  
  
"Now, listen here—"  
  
_(I need to let them know.)_  
  
_"SHUT UP!" _The room went silent at my outburst.__  
"Now listen up, you shitty little brothers. I hate to say this, but Karamatsu is right. We all need to work together to find the culprit. If we get this wrong, that shitty bear will probably execute all of us but the killer, like it or not. If we don't find evidence, we die.  
"And if we die, we'll all die _virgins_!"  
  
They all gasped at this revelation, except for Hatabou who cocked his head, and Chibita who just held his head in his hands, muttering something indecipherable.  
"Oh my god, you're right," Todomatsu whispered.  
"Right? So let's get investigating already!"  
I clapped my hands once and turned back to the still-dead Iyami, the pool of blood below him slowly growing larger.  
…  
  
_(Man, we are so screwed.)_____


End file.
